The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
Forklifts or similar load handling equipment are designed to handle pallets and the like by inserting a pair of forks or tines into access openings provided between opposing deck members or the pallet legs for a single deck pallet. The forks are mounted in parallel on a carriage which can be raised or lowered vertically and usually also tilted slightly, with the forks extending typically a distance of between three feet and seven feet, although different forklifts may utilize different sized forks. The front of each fork is tapered or beveled to allow for a small margin of error during the insertion process. In a warehouse setting, it may be desirable to operate the forklifts to raise loads many feet off the ground such that multiple pallets can be stored in a vertical column, minimizing the amount of floor space taken up by stored goods. Thus, even though the operator is seated on the forklift itself and is therefore a few feet above ground level, the load may need to be deposited onto or retrieved from a stack, rack or shelf many feet above the operator.
The proximity of the operator to the forks and pallet and the line of sight of the operator relative to the forks and pallet make it difficult for the operator to determine if the forks are at the preferential height prior to advancing the forks forward to retrieve the load onto the stack, rack or shelf. Under these conditions, operators estimate the correct height of the forks, then advance the forks forward to determine, by striking the shelf, rack, pallet or the load itself when retrieving, that the forks are misaligned. This technique can result in damage to the pallets or loads and to the shelves or racks. Line of sight problems additionally inhibit accurate positioning and placement of pallets and loads unto a surface such as a rack or shelf. While depositing a load, the forklift operator's line of sight may be compromised by the pallet and/or load. To overcome these sight difficulties, forklift operators guess where to position the pallet when unloading. Errant estimates can result in rack and shelf damage, load and merchandise damage, and precariously stacked loads that may topple, causing further load damage and possible bodily injury. Accordingly, a need exists for a guidance system to indicate to the operator the position of the forks relative to the pallet and a position of the pallet relative to potential objects such as the rack, shelf, and/or shelved loads and pallets. This combination enables new levels of warehousing efficiency by improving loading and unloading times and saving considerable expense and improving service levels by decreasing misplaced and damaged loads.